Field of the Invention
The present invention relates to an original reading apparatus equipped with an original tray, and control method for the original reading apparatus.
Description of the Related Art
An original reading apparatus in recent years is provided with an automatic original feeding device (hereinafter referred to as an “ADF”) that conveys an original automatically. An original reading apparatus optically reads an original conveyed by an ADF, and generates image data. The generated image data is stored in an image memory of the original reading apparatus.
Since a memory area that is needed to store image data is reserved in the image memory on the basis of a size of an original, it is necessary to grasp a size of an original before reading the original in order to reserve a needed memory area.
There is a known original reading apparatus that is provided with sensors that detect a length and a width of an original on an original tray of an ADF, specifies candidates of the size of the original that may correspond to the detected results, and selects the maximum size among the specified candidates as a temporary size when an original bundle that includes a plurality of sizes of originals (a size mixed original bundle) is stacked on the original tray (for example, see Japanese Laid-Open Patent Publication (Kokai) No. 2011-24098 (JP 2011-24098A)).
However, since the original reading apparatus in the above-mentioned publication selects the maximum size as a temporary size of the originals among the candidates of the size of the original on the basis of the detection results, a superfluous memory area is reserved in the image memory as compared with an actually needed memory area when the original to be read is smaller than the temporary size. As a result, a memory area needed for a next process may not be reserved, which keeps the next process waiting until a necessary memory area will be reserved. That is, the original reading apparatus in the above-mentioned publication may be in a suspended state until a memory area needed to perform a process after reading an original is reserved. As a result, the throughput of various processes performed by the original reading apparatus concerned drops.